Boat trailer winch casing



FIG. 1 is a side elevational view of a boat trailer winch casing showingmy new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof; and,

FIG. 5 is a bottom plan view thereof.

The ornamental design of a boat trailer winch casing, as shown.